Mike Moore had been in his new job exactly a month when he got a taste of what awaits him in Seattle. The new head of the World Trade Organization, on a scouting trip there for this month's WTO summit, was shouted at, interrupted, contradicted and insulted all day by anti-WTO protesters. The low point came when, during a panel discussion, a heckler compared him to Adolf Hitler.

"The WTO has become a target of grievances for everything that has gone wrong in the world in many decades," Moore, a former prime minister of New Zealand, said in an interview at the organization's headquarters here. "If we were not a democratic institution, we'd rebrand ourselves and start again."

When it was created five years ago, the WTO was hailed as the solution to the world's trade problems. It would oversee the frenetic pace of globalization--the elimination of trade and other barriers separating national economies that have accelerated since the end of the Cold War. It would also make certain that trade rules were enforced and would try to open international trade further in the name of world prosperity. In 1994, President Clinton called it "the boost we need to keep moving forward toward the 21st century."

Today, the 135-nation WTO, and the global open-trading system it stands for, are facing their greatest challenge since the organization was founded. Virulent opposition from both liberal and conservative politicians and groups around the world has increased and hardened since its inception. Tens of thousands of protesters from consumer, labor, environmental and other advocacy groups in more than 20 countries plan to be on hand when WTO member states gather in Seattle on Nov. 30 to create a framework for new global talks on reducing trade barriers.

WTO opponents accuse the trade body of being anti-labor and anti-environment and say it has favored corporate rights and profits over such issues as environmental and child-labor protection. They have proclaimed their message on dozens of Web sites. "Ten years of environmental activism reversed," says one; the WTO "has elevated corporate power above the sovereign powers of all nation states," says another. Members of such groups have been emboldened by their success in overturning an international accord on investment two years ago.

Right-wing politicians are finding fault with the WTO as well. Recent elections in Europe have elevated such far-right politicians as Christoph Blocher in Switzerland and Joerg Haider in Austria, both of whom owe at least some of their success at the ballot box to their abilities to tap into workers' fears that globalization puts their jobs and benefits at risk. In the United States, presidential candidate Patrick J. Buchanan, among other conservatives, has called for higher trade tariffs, and Buchanan has said the United States should withdraw from the WTO.

"What started off from decent motives about ecology is now being re-channelled into a giant movement of protest, fear and nationalism," said Denis MacShane, a Labor Party member of Britain's House of Commons who has written on challenges to the global trading system. "I respect the motives of the eco-campaigners and the labor campaigners," he said, "but they can end up being used by a more sinister, darker rationale."

At risk, say WTO defenders, is a system that has helped international trade grow by 37 percent since 1994, to $6.5 trillion last year, and, according to some studies, helped create 1.5 million new jobs worldwide. Thirty new countries have joined the WTO since its founding, and 30 more--most notably China--are trying to get in.

"The irony is that the living standards of hundreds of millions of people have been raised by expanding global trade," said Robert Hormats, vice chairman of the investment banking firm Goldman, Sachs International. "Increasingly, the doubters and dissenters have taken center stage, and the vast majority who have benefited are silent."

WTO officials say some of the fault lies with the trade body itself and acknowledge that its reputation as a secretive, closed bureaucracy is in part deserved. Arbitration hearings on challenges brought by one member state against another are not open to the public, for example.

The organization itself is often divided on policy--often between the Western industrialized world and developing nations who charge that they have not shared in the benefits of freer trade. "You cannot have two-thirds of the world population on the margins while two-thirds of world GDP [gross domestic product] is moving forward," said Youssef Boutros Ghali, Egypt's minister of economy and foreign trade.

Earlier this year, member nations could not even agree on a new WTO director general. Most Western countries supported Moore, while Asian members and others from developing countries favored Supachai Panitchpakdi, the deputy prime minister of Thailand. After months of public wrangling, the organization agreed to allow Moore to split one term with Supachai.

Members are also divided over what will be discussed in Seattle. The United States and Europe, which are engaged in bitter trade battles over European banana imports and hormone-treated beef, disagree on many issues before the trade body. Among them is whether genetically engineered foodstuffs are safe, as the United States contends, or pose a health and environmental risk, as European countries fear. The developing countries want the Seattle meeting to review existing trade agreements with an eye to revising them, while the industrialized world wants to embark on a new round of trade negotiations.

Some say the largest members, especially the United States, have failed to make the case for open trade or to take the lead in responding to the WTO's critics, and as the Seattle meeting approaches the Clinton administration has begun a campaign touting the benefits of free trade. "The core work of the WTO is under attack," said U.S. Trade Representative Charlene Barshefsky. "We need to make a response. . . . If we don't move forward, the risk of backsliding is very serious."

The WTO has become a lightning rod principally because of one innovation in its design. Unlike its predecessor institution, the General Agreement on Tariffs and Trade, the WTO was empowered to enforce trade rules and can force violating countries to change their laws or negotiate compensation agreements.

Countries can bring cases against each other before WTO arbitration panels, and the loser must change its practices or risk sanction. The current punitive tariffs imposed by the United States against Europe for its refusal to accept American beef treated with hormones, despite three WTO rulings in favor of the U.S. position, are an example.

To proponents, the dispute-resolution mechanism meant countries would be required to trade fairly; to opponents, it was a grievous wound to national sovereignty and has placed the profit motive ahead of humanitarian concerns.

Environmentalists in particular say the WTO was given a license to put commerce before environmental protection. When the WTO, acting on a challenge brought by India, Pakistan, Malaysia and Thailand, found against a U.S. requirement that all shrimp imported into the United States must be caught with fishing nets that do not ensnare sea turtles, environmental groups screamed. The WTO system "means an enormous shift of policymaking and decisions away from democratic accountable bodies to a secret, unaccountable bureaucracy," said Lori Wallach, director of Public Citizen's Global Trade Watch.

Organized labor says the WTO does not require developing countries to adhere to acceptable labor practices. Food-safety groups say WTO decisions dictate to countries what their citizens can eat and drink. French farmers ransacking McDonald's restaurants this summer blamed the WTO for allowing American tariffs on French Roquefort cheese. The leader of the French farmers' movement, Jose Bove, will be among those protesting in Seattle.

These organizations have argued their positions for years, but now the Internet has given them the means to organize more easily and to disseminate their views to a much wider audience. There are at least 45 anti-WTO Web sites, and anti-WTO groups in at least 20 countries have been planning Seattle strategy in conference calls once a week or so.

Moore concedes that the WTO has failed to respond adequately to its critics and that the WTO has not sufficiently oriented its policies toward its poorer members. He said it also has not made clear that its statutes do take into account environmental and health concerns under certain circumstances.

Moore, a former meat packer and labor activist, said he understands the concerns of the WTO protesters. He was unfazed by his clash with them in Seattle earlier this month, he said, and plans to meet with them again just before the summit.

"We don't want to put the wagons in a circle and regard the critics as an enemy," he said. "I just hope they are as reasonable as we try to be and that we engage in an intellectual, democratic way without any media terrorism."

CAPTION: WTO head Mike Moore gestures during news conference at a trade meeting in Berlin last week. U.S. Commerce Secretary William Daley is at right.